An airbag arrangement for protecting a vehicle occupant""s head/neck region is known. In the known arrangement, an airbag device is integrated with the vehicle seat. The airbag device has at least one airbag serving to protect the occupant""s heat/neck region. When the vehicle collides at its front or rear, the airbag inflates and deploys in the region of the head restraint of the vehicle seat. In the front collision, for example, the mass inertia initially moves the occupant in the direction of travel against a restraining system, such as a safety belt. The reaction force of the restraining system thereafter draws the occupant back into the vehicle seat. The airbag cushions the impact of the occupant""s back head/neck region to prevent or minimize a cervical spine whiplash trauma.
There is still a need to improve the protection capability, particularly during a vehicle rollover. The present invention addresses this need.
The present invention relates to a protection device for a passenger, namely an airbag arrangement for a vehicle and a method thereof. The present invention also includes a vehicle incorporating the airbag arrangement.
The airbag arrangement comprises an airbag device integrated with a vehicle seat, which can include a seat portion and a backrest extending from the seat portion, and a head restraint extending from the backrest. The airbag device can be integrated to at least one of the backrest and the headrest. The airbag device has at least one airbag for protecting the head/neck region of an occupant. According to the present invention, the airbag, in its substantially fully inflated state, extends forwardly and upwardly from the vehicle seat at an incline relative to the backrest for actively inducing a bent posture, that is, rolling or bending the occupant""s head toward the occupant""s chest.
The airbag device further includes a gas generator and a control unit for actuating the gas generator, which can be a multistage type. The control unit can be programmed to actuate the gas generator when the vehicle rolls over to fully inflate the airbag or when the vehicle is in a front or rear collision to partially inflate the airbag to an extent to position the airbag between the occupant""s head and the head restraint, without displacing the occupant""s head with the airbag.
The control unit can also be programmed to prevent the airbag from being deployed when the vehicle seat is in a predetermined position, identified as unsuitable for deploying the airbag, when the occupant is not strapped to a vehicle seatbelt, or when the vehicle seat is unoccupied. The control unit can also be programmed to output a signal for delaying deployment of a front airbag arranged in the vehicle in front of the vehicle seat when the airbag for protecting the head/neck region is to be deployed.
At least the head restraint supports the airbag in the substantially fully inflated state. The airbag in the substantially fully inflated state is also adapted to be also supported on a roof of the vehicle.
The airbag in the substantially fully inflated state can form a wedge-shaped profile, adapted to be positioned between the occupant""s head and the backrest for pressing the occupant""s head into the bent posture.
The airbag can include raised lateral margins extending along sides of the airbag. In the substantially fully inflated state, the raised lateral margins can extend along the direction of the seat portion.
The airbag can include a supporting portion and a holding portion. When the airbag is in the substantially fully inflated state, the holding portion is adapted for actively bending the occupant""s head, and the supporting portion is arranged between the vehicle seat and the holding portion. The holding portion can comprise a plurality of longitudinal chambers arranged side by side and communicating with each other, and the airbag in the inflated state, is adapted to extend along a longitudinal directions of a vehicle roof. The supporting portion also can include at least one elongate chamber that extends transversely to the longitudinal direction of the backrest.
The airbag can also be sub-divided into the holding portion and the supporting portion, the holding portion and the supporting portion forming a common chamber.
The airbag also can comprise a plurality of elongate chambers arranged serially next to one another and communicate with each other. In the substantially fully inflated state of the airbag, the elongated chambers can extend transversely to the longitudinal direction of the backrest. The individual chambers can be connected to one another serially so that the airbag, in the substantially fully inflated state, has a curved profile extending from the backrest for bending the occupant""s head.
The airbag or the holding portion in the substantially inflated state can also be configured to act as a chute, for pressing the occupant""s head into the bent posture and for guiding the bent head in a predefined manner during movement of the occupant in a fore and aft direction of the vehicle.
The airbag device can include a first airbag integrated with the backrest for bending the occupant""s head to assume the bent posture, and a second airbag integrated with the head restraint for supporting the first airbag. The second airbag can be arranged between the head restraint and the first airbag when the first and second airbags are in the substantially fully inflated state.
The airbag can also be substantially airtight so that the internal pressure in the airbag after inflation can be maintained for a period of about 5 to 7 seconds.
The head restraint can be adjustable between a lower position and an upper position. The airbag can be configured to raise the head restraint to the upper position during deployment to support the airbag over a larger area of the head restraint.
The seat covering of the backrest can have a tear line(s) for tearing apart in a predefined manner so that the seat covering torn from the backrest can be arranged between the occupant and the airbag in the substantially inflated state.
The vehicle according to the present invention can incorporate all or some of the above features of the airbag arrangement.
The method of protecting an occupant of a vehicle according the present invention can include: providing an airbag device integrated with a vehicle seat, the airbag device having at least one airbag for protecting the head/neck region of an occupant; and fully inflating the airbag when the vehicle rolls over to bend the head of the occupant toward the chest of the occupant into a bent posture with the airbag as the airbag is fully inflating. The method can further include partially inflating the airbag when the vehicle is in a front or rear collision to an extent to position the airbag between the occupant""s head and a head restraint of the vehicle seat, without displacing the occupant""s head with the airbag. It can further include preventing the airbag from being deployed when the vehicle seat is in a predetermined position, identified as unsuitable for deploying the airbag, when the occupant is not strapped to a vehicle seatbelt, or when the vehicle seat is unoccupied. Moreover, it can include delaying deployment of a front airbag arranged in the vehicle in front of the vehicle seat when the airbag for protecting the head/neck region is to be deployed. The other features described in the airbag arrangement can be included in the present method.